Custom events in Google Analytics 4 for Ajax search

I have an search feature on my website. Sending text box value to a controller using Ajax and reading response. I want to track the text box value in Google Analytics 4. I have created a custom event but confused what will be my matching condition (parameter name, operator and value) ? enter image description here

window.gtag('event','search_keyword',{   search_term_input : $  ('#txt-search').val(),   country_code : 'UK' }); 

Request is reaching to GA4 and event is visible in Realtime tracking dashboard. I have created a custom dimension for search_keyword event and when generating report it search term is not available. Report display as "not set". enter image description here